<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <style>
    .upper {
      text-transform: uppercase;
    }
    .lower {
      text-transform: lowercase;
    }
    .app {
      width: 100%;
      height: 200px;
      display: flex;
    }
    .app .left {
      width: 200px;
      background-color: yellow;
    }
    .app .right {
      flex: 1;
      background-color: red;
      overflow-y: auto;
    }
    .right .content {
      width: 800px;
    }
  </style>
  <body>
    <div class="upper">huhuh 一二34</div>
    <div class="lower">ABCDEFG 一二34</div>
    <div class="app">
      <div class="left"></div>
      <div class="right">
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div>11</div>
        <div class="content">
          <p>pppp</p>
          <p>pppp</p>
        </div>
      </div>
    </div>
  </body>
</html>
